LS3.1 Week4 Lec11

LS3.1 Week4 Lec11

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Unformatted text preview: he lagging strand is made discontinuously, has frags of DNA DNA synthesis at both replication forks Leading strand lagging strand (Okazaki fragments) 100-400 base pairs until a new Okazaki fragments Replication Fork semiconservative DNA Replication Mechanism Both strands are duplicated. Leading strand and lagging strand Enzyme: DNA polymerase Substrates: Deoxyribonucleoside triphosphates Direction of Synthesis: 5' to 3' Initiation requires a "primer" with a 3'OH. Chemistry: 3'OH attacks alpha phosphate of incoming dNTP RNA polymerase- kinase Many accessory proteins are required Key enzymes and accessory proteins involved in DNA replication Helicase Single strand DNA binding protein (SSB) DNA topoisomerase Primase DNA polymerase RNase H DNA Ligase Sliding clam protein Helicase unwinds dsDNA to create ssDNA at a junction, it uses ATP to separate the DNA strand always moves from ss to ds SSB (single strand DNA binding protein) bind and stabilize ssDNA cooperative binding promotes another ssb protein to bind next to it they are sequence non specific because they are supposed to bind any possible regions Cooperative binding ensures that ssDNA is rapidly coated by SSB as it emerges from the DNA helicase Important to stabilize the separated strands DNA topoisomerase Unwinding of the double helix at the replication fork causes supercoiling of the DNA helix Topoisomerases all...
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This note was uploaded on 04/26/2013 for the course LIFE SCIEN 3 taught by Professor Wong during the Spring '13 term at UCLA.

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